@misc{cryptoeprint:2013:594,
author = {Yuan Tian and Rongxin Sun and Xueyong Zhu},
title = {A Local-Global Approach to Solving Ideal Lattice Problems},
howpublished = {Cryptology ePrint Archive, Report 2013/594},
year = {2013},
note = {\url{http://eprint.iacr.org/}},
}
You will need the url.sty package (comes with most LaTeX installations) for the last line. Otherwise, remove the \url command.